Many fish are commercially produced in hatcheries and fish stock farms because under a controlled environment and feeding they may grow faster and are of better quality. It has been found that the rate of growth of fish as compared to the volume of the habitant in which they are grown is directly proportional thereto. Thus, the fish placed in a tank of a given volume will grow to just a certain maximum size within that tank and unless placed in a larger tank will not grow any larger.
Small fish when placed in with larger fish are unable to defend themselves and are often eaten or are casualties of fights with the larger fish. Thus, it is desirable that fish of the same size be placed in one tank.
Heretofore the transfer of fish from a smaller tank to a larger tank has involved the use of one's hands or a net to transfer them often resulting in the bruising or other injury to the fish in the transfer procedure. When a fish is injured it may die or its rate of growth is decreased until such injury has healed. The injury or killing of fish in this process reduces the efficiency of production and the quality of fish produced.
This invention utilizes the phenomena that fish may be herded or driven much the same as cattle by creating a splash or other motion behind them, thus permitting them to be herded from one tank to the other without manual handling.